As a result of advancements in computer technology, there has been a rapid development of high performance compact computers, such as, notebook-type personal computers, and computers with card connectors that have two receiving slots designed for receiving ISO standard IC cards or smart cards (hereafter“smart cards”) and PCMCIA standard IC cards (hereafter“IC cards”). As shown in FIG. 9, the smart cards 100 have a plurality of terminal parts 101 on a main surface of the smart card 100 and a depth of 85.6 mm, a width of 54 mm, and a thickness of 0.68 to 0.84 mm. There are three types of IC cards. As shown in FIG. 10, type IIC cards 110 have a connector part 111 on one end portion of the IC card 110 and have a depth of 85.6 mm, a width of 54 mm, and a thickness of 3.3 mm. The type IIC cards 110 are used as semiconductor memory cards. Type II IC cards have a depth of 85.6 mm, a width of 54 mm, and a thickness of 5 mm. The type II IC cards are used as modem cards. Type III IC cards have a depth of 85.6 mm, a width of 54 mm and a thickness of 10.5 mm. The type III IC cards are used as hard disk cards.
When the dimensions of the smart card 100 and the dimensions of the IC cards are compared, it is apparent that while the depth and width of the smart card 100 and the IC cards are the same that the thickness of the cards vary. The smart card 100 is comparatively thinner than the three types of IC cards. As a result, the height in a direction of thickness of the receiving slot that receives the smart card 100 is configured to be small, and the height in the direction of thickness of the receiving slot that receives one of the IC cards is configured to be large to facilitate receipt of the respective card in the card connector.
If a user inserts the smart card 100 with the smaller thickness into the receiving slot used for the IC cards with the larger thickness, there is a danger that a plurality of pin contacts arranged in the larger receiving slot used for the IC cards or a portion of the housing, etc., will be bent and/or damaged by an end portion of the smart card 100. Additionally, if the plurality of pin contacts are not damaged, the user may mistakenly believe that the smart card 100 has been inserted into the appropriate receiving slot and will be unable to operate the computer normally when a power supply of the computer is switched on.
Several attempts have been made to prevent the erroneous insertion of the smart card into the larger receiving slot. For example, FIG. 11 shows an IC card socket 200 that prevents the erroneous insertion of a thin card into a receiving slot used for cards with a large height (see JP11-39,435A). The IC card socket 200 comprises a plurality of pin contacts 201 electrically connected to an IC card 110. A pair of guide rails 202 guide the insertion of the IC card 110 toward the pin contacts 201. A set of upper and lower thickness detecting levers 203 are disposed on one of the guide rails 202 and are pivotally supported by a pivoting shaft 206. Inserted-object clamping parts 205 are disposed on end portions of the respective thickness detecting levers 203 and are located on a side of a card insertion opening to detect the thickness of objects that are inserted into the guide rails 202. Shutter parts 204 are disposed on the end portions of the respective thickness detecting levers 203 and are located on the side of the pin contacts 201.
When an IC card 110 having a large thickness is inserted into the IC card socket 200 along the guide rails 202, the inserted-object clamping parts 205 open, and the upper and lower thickness detecting levers 203 accordingly pivot about the pivoting shaft 206, as shown in FIG. 11(A). When the thickness detecting levers 203 open, the shutter parts 204 also open so that the IC card 110 may be connected to the pin contacts 201. On the other hand, when a smart card 100 with a small thickness is inserted along the guide rails 202, the upper and lower thickness detecting levers 203 do not open, as shown in FIG. 11(B). Accordingly, the shutter parts 204 remain closed, such that the insertion of the smart card 100 is checked by the shutter parts 204.
FIG. 12 shows another example of an IC cartridge reader 300 with means for preventing the erroneous insertion of an inappropriate IC cartridge (see JP2-35,584A). The IC cartridge reader 300 comprises a chassis 301 with an IC cartridge insertion opening 302 and a shutter means 303. The shutter means 303 consists of a shutter main body 304 and a spring member 305 disposed in a vicinity inside of the IC cartridge insertion opening 302. The spring member 305 supports the shutter main body 304 so that the shutter main body 304 can open and close. An erroneous insertion preventing projection 306 is formed on the shutter main body 304. A cut-out 311 is formed in an end portion of an IC cartridge 310 in a position corresponding to the erroneous insertion preventing projection 306.
As shown in FIG. 12 (A), when an appropriate IC cartridge 310 is inserted in the IC cartridge insertion opening 302, the erroneous insertion preventing projection 306 passes through an interior of the cut-out 311, and a tip end of the IC cartridge 310 contacts the shutter main body 304. Since an inclined surface 304 a is formed on the shutter main body 304, a down oriented component force of the insertion force of the IC cartridge 310 is generated by the inclined surface 304 a such that the shutter main body 304 is driven downward against the elasticity of the spring member 305 to allow insertion of the IC cartridge 310. On the other hand, when an inappropriate IC cartridge 310, e.g. an IC cartridge 310 which does not have a cut-out 311 or an IC cartridge 310 in which the position of the cut-out 311 is different, is inserted into the IC cartridge insertion opening 302, a tip end of the IC cartridge 310 contacts the erroneous insertion preventing projection 306, as shown in FIG. 12 (B). Since the erroneous insertion preventing projection 306 is formed perpendicular to the direction of insertion of the IC cartridge 310, no downward-oriented component force is generated in the shutter main body 304, and the shutter main body 304 is not opened. As a result, the insertion of inappropriate IC cartridges 310 is prevented.
Several problems and disadvantages, however, have been encountered with the IC card socket 200, shown in FIG. 11, and the IC cartridge reader 300, shown in FIG. 12. In the case of the IC card socket 200, the mechanism for preventing the erroneous insertion of the thin cards is effective only in cases where there is only one receiving slot. The mechanism can not be applied to card connectors having at least two receiving slots disposed adjacent to each other above and below wherein one of the receiving slots receives the thin cards and the other of the slots receives the thick cards. Further, the construction of the mechanism is complicated so that not only is the manufacturing cost of the IC card socket 200 high, but the IC card socket 200 is also bulky. In the case of the IC cartridge reader 300, the IC cartridge reader 300 can not be applied to ordinary IC cards and smart cards, because a special IC cartridge 310 which has a cut-out 311 formed in the end portion is required to prevent erroneous insertion of the cards.